System Restore Win 10

Help Please!
I am a dummy with computing…
Why is there no system restore in Win 10? There used to be a Back up & Restore (Win7) facility. This no longer works. When I try to back up on my remote hard drive it says failed or similar.

Firefox updated the other day and screwed up my computer – text sizes and display all changed. I can make no sense of it and now have to put up with unsatisfactory displays. No amount of adjustment can get it back to wher eit was. Beforehand I would just run System Restore which saved my life many times. Now it appears no longer to exist.

Thanks